Comment 12 for bug 1510234

Reviewed: https://review.openstack.org/503939
Committed: https://git.openstack.org/cgit/openstack/masakari/commit/?id=2c4574bfdcf9bd08efcb3c82becb26787a635338
Submitter: Zuul
Branch: master

commit 2c4574bfdcf9bd08efcb3c82becb26787a635338
Author: Dinesh Bhor <email address hidden>
Date: Wed Sep 13 16:12:33 2017 +0530

    Make eventlet hub use a monotonic clock

    If system time is adjusted first forward and then backward while a
    masakari-engine service is running, then the periodic tasks stops
    for the duration of time the system clock was adjusted backward.

    This was supposed to be fixed by the following patch to oslo.service
    https://review.openstack.org/#/c/286838/ , but the order of imports
    in unit tests and production code is different, so masakari services
    end up starting with the default eventlet hub, that does not use a
    monotonic clock and, thus, is affected by changes of system time.

    Testing the change done in the patch is problematic, as it's a
    subject of imports order and is not reproduced in functional or
    unit tests (oslo_service is always imported earlier than eventlet
    hub is initialized, so it just does "the right thing").
    The alternative is to make an assertion when services start.

    Co-Authored-By: Roman Podoliaka <email address hidden>
    Closes-Bug: #1510234
    Change-Id: I9d917b3151d9cdf7340a173b5baf98def63c76cd